代码如下

<?php
$data = <<<XML
<?xml version="1.0" encoding="UTF-8"?>
<dict>
 <key>百度</key>
 <pos></pos>
 <acceptation>2132</acceptation>
 <sent>
  <orig>百度一下</orig>
  <trans>baidu.com</trans>
 </sent>
</dict>
XML;

$xml = simplexml_load_string($data);
header("Content-Type: text/html; charset=UTF-8");
print_r($xml);
echo "<br />".trim($xml->sent->orig); //百度一下
echo "<br />".trim($xml->key); //百度
?>

OK